Alarm in a detach garage
- Thread starter beaumeri
- Start date
Since you're looking at an Aux supply, if you go with a 212S, you're golden and it gives you a switchable output out there. If you choose another manufacturer, I would recommend supervision options to include AC loss and low battery. Also make sure you select one that has 0V loss on switch to battery and size the batteries larger than the standby time on the panel. If you're going to have an unheated space, make sure to take into consideration the correction factors based on temperature for the batteries. I think Altronix and Yuasa had the specific tables I can remember, but I want to say the correction factor is .60 or .75 on the listed Ah for temperatures less than 25* F.
I wouldn't worry about the post regarding the ground question, it's not relevant. The thing to consider is placing a surge on the data line directly bonded to the EG where it exits the ground or ground rod. Ditek gives the valid guidelines for their units
I wouldn't worry about the post regarding the ground question, it's not relevant. The thing to consider is placing a surge on the data line directly bonded to the EG where it exits the ground or ground rod. Ditek gives the valid guidelines for their units
123
Senior Member
Thanks for confirming my suspicions ...
@beaumeri
It's never fun to debug signaling equipment with floating or dissimilar grounds; you're fine.
I think you're missing the point 123.
The alarm panel and a separate aux power supply need to share a common negative (ground) which is different than an EG, if you are powering bus devices off of it, however is isn't necessary if you are only powering protective devices.
In the case of surge protection, you would need a building ground to connect the surge protection to and the protectors would be grounded to that as close as practicable following normal ground and surge methods...the most important is that the path to ground be shorter than the cabling feeding to the surge, you don't want to make tight wire bends, stuff like that.
The panel is not referencing the EG source at any point, it's actually recommended to NOT connect the M1 to an EG and the only purpose of connecting the panel to the EG here is for suppression purposes, which should be installed on the AC mains feeding the main panel, telco connection, any data lines leaving the building (required if installing fire alarm) or any IDC circuit for fire alarm leaving the building. Aux supplies should also have their mains connection surge protected as well. IMHO, the connection for the XEP should really have a surge as well. In the case of the panel surges, those would be bonded together, however the data leaving the building would be surged as noted above.
The alarm panel and a separate aux power supply need to share a common negative (ground) which is different than an EG, if you are powering bus devices off of it, however is isn't necessary if you are only powering protective devices.
In the case of surge protection, you would need a building ground to connect the surge protection to and the protectors would be grounded to that as close as practicable following normal ground and surge methods...the most important is that the path to ground be shorter than the cabling feeding to the surge, you don't want to make tight wire bends, stuff like that.
The panel is not referencing the EG source at any point, it's actually recommended to NOT connect the M1 to an EG and the only purpose of connecting the panel to the EG here is for suppression purposes, which should be installed on the AC mains feeding the main panel, telco connection, any data lines leaving the building (required if installing fire alarm) or any IDC circuit for fire alarm leaving the building. Aux supplies should also have their mains connection surge protected as well. IMHO, the connection for the XEP should really have a surge as well. In the case of the panel surges, those would be bonded together, however the data leaving the building would be surged as noted above.
123
Senior Member
@beaumeri, if you want more information, you can start here http://www.bapihvac.com/content/uploads/2010/07/Understanding-Ground-Loops.pdf and Google for more, if you wish.
OP,
If you are interested here is my detached garage panel with a 212S (battery below), an XIN, and an M1OVR.
The little black box on the bottom middle is a Ditek Surge protector. There is also the exact same surge protector at the entry point in the house. That wiring is in a "temporary" state so no pics of that end...*vomit*
The M1 is in the house in the "middle" of the bus. There is also a keypad in the garage which is where the terminating resistor is used. The other terminating resistor is in the house at the other Keypad on the end of the 485 run.
No CAT5 or DBH (or DBHR) used in this installation. All wiring is point to point with 2PR22 cable.
If you are interested here is my detached garage panel with a 212S (battery below), an XIN, and an M1OVR.
The little black box on the bottom middle is a Ditek Surge protector. There is also the exact same surge protector at the entry point in the house. That wiring is in a "temporary" state so no pics of that end...*vomit*
The M1 is in the house in the "middle" of the bus. There is also a keypad in the garage which is where the terminating resistor is used. The other terminating resistor is in the house at the other Keypad on the end of the 485 run.
No CAT5 or DBH (or DBHR) used in this installation. All wiring is point to point with 2PR22 cable.
Attachments
@ 123....you're referencing the wrong subject and your suspicions are wrong.
The M1 will not be referencing EG at all, neither will an aux power supply. If you tie a common negative to the panel from the aux supply, then electrically speaking, both are at the same potential and common. Since neither would be grounded, there's no potential for a ground loop. If the aux supply is hardwire connected to an EG, that's another ballgame. None of the protective circuits have a ground, nor do they have a reference to EG. The COM on the panel is not the same as an EG.
In the case of the surges, the only purpose of their connection to EG is to bleed off the breakover current to protect the panel and the additional hardware.
The M1 will not be referencing EG at all, neither will an aux power supply. If you tie a common negative to the panel from the aux supply, then electrically speaking, both are at the same potential and common. Since neither would be grounded, there's no potential for a ground loop. If the aux supply is hardwire connected to an EG, that's another ballgame. None of the protective circuits have a ground, nor do they have a reference to EG. The COM on the panel is not the same as an EG.
In the case of the surges, the only purpose of their connection to EG is to bleed off the breakover current to protect the panel and the additional hardware.
Enlighten me, since you know something that is different in this case.
Tell me how a panel that does not reference the EG would get a ground loop if it is electrically isolated from such with no ground reference whatsoever, assuming the cabling that is attached to such does not have a ground fault?
Tell me how a panel that does not reference the EG would get a ground loop if it is electrically isolated from such with no ground reference whatsoever, assuming the cabling that is attached to such does not have a ground fault?
123
Senior Member
With respect, I honestly have no desire to engage you any further. I've read a few your posts in other threads and, for a knowledgeable individual, you are surprisingly disdainful of people's opinions. Do your own homework; measure your M1's databus voltages, with respect to EG. What results would you expect to see "if it is electrically isolated from such with no ground reference whatsoever"?
Feel free to have the last word on this topic; whatever conclusion you arrive at, pro or con, makes no difference to me.
Feel free to have the last word on this topic; whatever conclusion you arrive at, pro or con, makes no difference to me.
I guess you bested me.
I metered 5 separate M1's, including my own, and 2 EZ8's and when I meter the bus to EG, I get 0-.5V (which I can attribute to the meter itself), so in real world application of multiple panels, I have 0V to ground, and Meg resistance....so no continuity either.
Care to explain your knowledge when I have panels that are electrically isolated in relation to EG? I'm not experiencing what you are calling a ground loop or a panel that is referencing EG.
I metered 5 separate M1's, including my own, and 2 EZ8's and when I meter the bus to EG, I get 0-.5V (which I can attribute to the meter itself), so in real world application of multiple panels, I have 0V to ground, and Meg resistance....so no continuity either.
Care to explain your knowledge when I have panels that are electrically isolated in relation to EG? I'm not experiencing what you are calling a ground loop or a panel that is referencing EG.
